Common field effect transistors (FETs) utilize an insulated gate that creates a channel between a source and a drain. FETs rely on a band edge shift using an applied gate voltage to create the channel. Other types of transistors have also been explored. For example, velocity/mobility modulation transistors rely on the real-space transfer of carriers between two adjacent materials with different mobilities. Similarly, quantum modulation transistors (QMT) are based on the constructive and destructive interference of the wavefunctions in the channel by electrically changing the T-shaped box dimensions. Furthermore, quantum effects in various planar heterostructures based on the modulation-doped field-effect transistor (MODFET) principle have been explored, where the field-effect is used to perturb the barriers for carriers flowing between the source and the drain electrodes. The localization of the state near band edges due to disorder in the Anderson localization is also a relevant concept, which leads to a mobility edge, but this effect is limited by the thermal limit.